1. Field of the Invention
The present invention relates to improvements in or relating to apparatus for heating bodies of water such as swimming pools and methods of heating swimming pools or the like bodies of water.
2. Description of the Prior Art
Most swimming pools that are to be used require some degree of temperature control in order to maintain the same at an acceptable level for swimming, for example 74.degree. to 85.degree. F. Traditionally, oil fired heating has been used to transfer heat to water that is being added to the swimming pool or which is being circulated with respect to the main body of the water of the swimming pool. Other forms of heat transfer of the circulatory type are also well known. More recently, a circulatory approach has been adapted based on solar energy as the source of heat for the heat exchanger. Many different forms of solar heat collector of this type are known. However such systems require complicated plumbing and are expensive in order to maintain the same at their optimum efficiency.
It is well known that a black body will absorb electromagnetic radiation more readily than a light coloured body. It is well known too, that a certain amount of penetration of the sun's rays occurs through the water contained in a swimming pool. Such solar heat, however, is largely reflected back through the water (without substantially heating the same) by the normally favoured more attractive light coloured base of the swimming pool. Anyway to coat the bottom of the swimming pool completely with a black surface while not only making the pool unattractive to swimmers also introduces difficulties of maintaining the temperature of water in the pool below a certain level during high sunlight summers.
The use of a black surface under a film of water in order to absorb solar radiation and to pass the heat gained thereby to the water is known. For example some pools employ a black surface around the periphery thereof under a film of water for this purpose. One such pool of this type was known in Christchurch, New Zealand 20 years ago. No such construction however is attractive and fully acceptable to swimmers in such a pool. Moreover such a construction which requires special construction does not allow for a great degree of control without the use of expensive and unsightly covers. There is therefore a need for some means whereby solar energy can be simply collected and passed to water in a body of a swimming pool or the like so as to provide a base source of temperature enhancement. There should also be some amount of control of the basic enhancement. Of course with a swimming pool with an existing heating system, the amount of oil, gas or electricity used thereby would be severely limited i.e. it would only be needed to maintain the pool temperature over poor sunlight periods or where the temperature of the pool is to be boosted for some reason or other above a temperature that is not attainable by the solar heat collecting system.
It is therefore an object of the present invention to provide apparatus, means and methods which will go at least some way to meet the abovementioned desiderata or which will at least provide the public with a useful choice.